Planar conjugated compounds and their applications for organic electronics

Abstract

The invention relates to organic semiconducting materials, methods for their preparation and organic electronic devices incorporating the said organic semiconducting materials. The organic semiconductors contain a compound of formula (I) Ar 1 =(Qu) m =Ar 2   (I) where Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, and Ar 1 and Ar 2 each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms. The compounds of formula may generally form an H-shaped molecular structure. The said organic semiconducting materials could be used as the active layers for organic electronic devices, e.g. thin film transistors, photovoltaic cells, photo detectors, light emitting diodes, memory cells, sensors etc.

1 . A compound of formula (I):
   Ar 1 =(Qu) m =Ar 2   (I)
   
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, and is optionally substituted by one or more substantially planar conjugated aromatic structures independently chosen, and 
 m is from 1 to 20; 
 with the proviso that the compound of formula (I) is not a compound of formula (1) 
 
       
         
           
           
               
               
           
         
       
     
     
         2 . A compound of formula (Ib) 
       
         
           
           
               
               
           
         
       
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, 
 Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 , Ar 8 , Ar 9  and Ar 10  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, and optionally containing one or more heteroatoms independently chosen, 
 m is from 1 to 20, and 
 j, k, n, p each, independently, is from 0 to 20, 
 q is 1 or more. 
 
     
     
         3 . The compound of  claim 1 , wherein the substantially planar conjugated aromatic structure forms a rigid substantially planar conjugated aromatic structure. 
     
     
         4 . The compound of  claim 1 , wherein the substantially planar conjugated aromatic structure forms a bridged substantially planar conjugated aromatic structure. 
     
     
         5 . The compound of  claim 1  having a bandgap of <2.0 eV. 
     
     
         6 . The compound of  claim 1 , wherein =Qu= is 
       
         
           
           
               
               
           
         
       
       where each X, independently, is CH, N or P, and optionally contains, one or more substitutents. 
     
     
         7 . The compound of  claim 1 , wherein the substitutions on Ar 1  to Ar 10 , may be one or more electron donating groups, electron withdrawing groups or a combination thereof. 
     
     
         8 . A compound of formula 2, 3 or 4 
       
         
           
           
               
               
           
         
       
     
     
         9 . A semiconductor device having a semi-conductor layer containing the compound of formula (I) or formula (Ib)
   wherein Ar 1 =(Qu) m =Ar 2   (I),
   
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, and is optionally substituted by one or more substantially planar conjugated aromatic structures independently chosen, and 
 m is from 1 to 20; 
 
       and wherein 
       
         
           
           
               
               
           
         
       
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, 
 Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 , Ar 8 , Ar 9  and Ar 10  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, and optionally containing one or more heteroatoms independently chosen, 
 m is from 1 to 20, and 
 j, k, n, p each, independently, is from 0 to 20, 
 q is 1 or more. 
 
     
     
         10 . A semiconductor device having:
 a source electrode and a drain electrode separated from a gate electrode by a gate dielectric; and   a semiconductor layer having the compound of formula (I) or formula (Ib) either over or under the source electrode and the drain electrode to form a charge transport channel,   
       wherein
   Ar 1 =(Qu) m =Ar 2   (I)
 
 
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, and is optionally substituted by one or more substantially planar conjugated aromatic structures independently chosen, and 
 m is from 1 to 20; 
 
       and wherein 
       
         
           
           
               
               
           
         
       
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, 
 Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 , Ar 8 , Ar 9  and Ar 10  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, and optionally containing one or more heteroatoms independently chosen, 
 m is from 1 to 20, and 
 j, k, n, p each, independently, is from 0 to 20, 
 q is 1 or more. 
 
     
     
         11 . The semiconductor device of  claim 10 , wherein the device is a transistor, light emitting semiconductor, photoconductor, current limiter, thermister, p-n junction, field-effect diode or Schottky diode. 
     
     
         12 . An organic thin film transistor device containing:
 a plurality of electrically conducting gate electrodes disposed in or on a substrate;   a gate insulator layer disposed in or on the electrically conducting gate electrodes;   an organic semiconductor layer disposed in or on the gate insulator layer substantially overlapping the gate electrodes; and   a plurality of sets of electrically conductive source and drain electrodes disposed in or on the organic semiconductor layer such that each of the sets in alignment with each of the gate electrodes;   wherein the organic semiconductor layer is the compound of formula (I) or formula (Ib),
   wherein Ar 1 =(Qu) m =Ar 2   (I),
 
   
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, and is optionally substituted by one or more substantially planar conjugated aromatic structures independently chosen, and 
 m is from 1 to 20; 
 
       and wherein 
       
         
           
           
               
               
           
         
       
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, 
 Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 , Ar 8 , Ar 9  and Ar 10  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, and optionally containing one or more heteroatoms independently chosen, 
 m is from 1 to 20, and 
 j, k, n, p each, independently, is from 0 to 20, 
 q is 1 or more. 
 
     
     
         13 . A process for preparing an organic thin film transistor device containing the steps of:
 depositing a plurality of electrically conducting gate electrodes in or on a substrate;   depositing a gate insulator layer in or on the electrically conducting gate electrodes;   depositing a layer of the compound of formula (I) or formula (Ib) in or on the insulator layer such that the layer substantially overlaps the gate electrodes; and   depositing a plurality of sets of electrically conductive source and drain electrodes in or on the layer such that each of the sets is in alignment with each of the gate electrodes;   thereby producing the organic thin film transistor device,
   wherein Ar 1 =(Qu) m =Ar 2   (I)
 
   
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, and is optionally substituted by one or more substantially planar conjugated aromatic structures independently chosen, and 
 m is from 1 to 20; 
 
       and wherein 
       
         
           
           
               
               
           
         
       
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, 
 Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 , Ar 8 , Ar 9  and Ar 10  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, and optionally containing one or more heteroatoms independently chosen, 
 m is from 1 to 20, and 
 j, k, n, p each, independently, is from 0 to 20, 
 q is 1 or more. 
 
     
     
         14 . An organic thin film transistor having an active layer containing the compound of formula (I) or formula (Ib)
   wherein Ar 1 =(Qu) m =Ar 2   (I)
   
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, and is optionally substituted by one or more substantially planar conjugated aromatic structures independently chosen, and 
 m is from 1 to 20; 
 
       and wherein 
       
         
           
           
               
               
           
         
       
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, 
 Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 , Ar 8 , Ar 9  and Ar 10  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, and optionally containing one or more heteroatoms independently chosen, 
 m is from 1 to 20, and 
 j, k, n, p each, independently, is from 0 to 20, 
 q is 1 or more. 
 
     
     
         15 . A photovoltaic cell having an active layer containing the compound of formula (I) or formula (Ib),
   wherein Ar 1 =(Qu) m =Ar 2   (I)
   
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, and is optionally substituted by one or more substantially planar conjugated aromatic structures independently chosen, and 
 m is from 1 to 20; 
 
       and wherein 
       
         
           
           
               
               
           
         
       
       where
 each Qu is independently a substituted or unsubstituted, substantially planar 5 to 8 membered conjugated ring, optionally fused to one or more aromatic moieties independently chosen, and may contain one or more heteroatoms independently chosen, 
 Ar 1  and Ar 2  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, optionally having one or more heteroatoms independently chosen, 
 Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 , Ar 8 , Ar 9  and Ar 10  each independently is a substituted or unsubstituted, substantially planar conjugated aromatic structure having from 5 to 50 carbon atoms, and optionally containing one or more heteroatoms independently chosen, 
 m is from 1 to 20, and 
 j, k, n, p each, independently, is from 0 to 20, 
 q is 1 or more. 
 
     
     
         16 . The compound of  claim 2 , wherein the substantially planar conjugated aromatic structure forms a rigid substantially planar conjugated aromatic structure. 
     
     
         17 . The compound of  claim 2 , wherein the substantially planar conjugated aromatic structure forms a bridged substantially planar conjugated aromatic structure. 
     
     
         18 . The compound of  claim 2 , having a bandgap of <2.0 eV. 
     
     
         19 . The compound of  claim 2 , wherein =Qu= is 
       
         
           
           
               
               
           
         
       
       where each X, independently, is CH, N or P, and optionally contains, one or more substitutents. 
     
     
         20 . The compound of  claim 2 , wherein the substitutions on Ar 1  to Ar 10 , may be one or more electron donating groups, electron withdrawing groups or a combination thereof.